Product Description:
The new Wavetrac® is a helical-gear limited-slip differential, but unlike other gear differentials, the Wavetrac® was designed from a clean sheet using state-of-the-art knowledge and engineering to be a better differential than any other.

Wavetrac gives you quicker acceleration and faster cornering by driving both drive wheels instead of just one. And, it offers improved no-load performance when compared to other helical gear differentials on the market.

Ordering:
Website: All website orders can be done directly through our site http://www.namotorsports.net. Please just click any of the product links above to go directly to our site.
Phone: Call us toll free at 1-877-NAMOTORS to place your order over the phone.

Payment:
Since this is a pre-order, you will be billed for the product when you place the order. This will ensure that you will receive one of the sets we have coming in. We accept all major credit cards, Paypal, money orders and wire transfers. If you are interested in paying using a money or wire transfer, please call us toll free at 1-877-NAMOTORS

Might want to mention these will only work for 1ers with slushies. All manual tranny 1ers drew the suckage card, with welded diffs. Also might want to mention gear ratios (not mentioned on your site either).

Might want to mention these will only work for 1ers with slushies. All manual tranny 1ers drew the suckage card, with welded diffs. Also might want to mention gear ratios (not mentioned on your site either).

I have updated the info on our website and I apologize for the mistake. You are correct any 1 series or 3 series built after March of 2007 will have a welded differential.

The Wavetrac differential does not change the gear ratio. This is a common misconception. You can purchase a new ring and pinion setup to change the gear ratio when you are installing the Wavetrac diff, however, if you just install the diff, you will have the same ratio as when you had the stock BMW diff. I hope this info helps.

Very good question. Wavetrac technology is brand new and I've posted how they describe it below from their site. Also, since these are designed and made in California, this helps keep the price down compared to Quaife.

Wavetrac Technical Details:

To best understand how the Wavetrac® is truly different from the other gear differentials on the market, you first have to understand the primary problem that the Wavetrac® solves.

The problem: Loss of drive during zero or near-zero axle-load conditions.
Zero axle-load is a condition that occurs during normal driving, but creates the most noticeable problems when driving in extreme conditions. Zero or near-zero axle-load is the condition that exists when there is ‘no-load’ applied through the drivetrain, when one drive wheel is nearly or completely lifted (often in aggressive cornering). It also occurs during the transition from engine driving a vehicle to engine braking and back, even with both drive wheels firmly on the ground.

Here’s how that loss of drive hurts you:

1) If you lift a wheel, all gear diffs except Wavetrac®, will NOT power the other wheel.

2) During the transition from accel to decel, all gear diffs except Wavetrac®, do nothing.

Why does this happen?

All gear LSDs (including Torsen®, Truetrac®, Quaife®, Peloquin, OBX, etc.) work in basically the same manner: they divide the drive torque between the two axles, applying drive to each side, up to the available grip of each tire. The amount of drive torque one wheel can get over the other is described as the bias ratio, a measure of the torque split across the axle.

Standard, open differentials have a bias ratio of 1:1. They can only apply as much drive torque as there is available traction at one wheel. When one wheel loses grip, the total available drive is lost as well (at a 1:1 ratio). All your power goes out the slipping wheel - along the path of least resistance.

Torque biasing differentials offer increased bias ratios over open differentials. For example, if a diff has a bias ratio of 2.5:1, then it can apply drive torque to the wheel with the most traction (gripping wheel) at 2.5 times the traction limit of the wheel with the least traction (slipping wheel). This is a significant improvement over an open diff… most of the time.

The problem is that when one tire has LITTLE or NO grip (zero axle-load), the other wheel gets ZERO DRIVE, because (basic math here): 2.5 x 0 = 0.

Lift a wheel (or substantially unload a wheel) and you get zero axle-load on that side - that means that during the time the wheel is unloaded, the typical diff will NOT power the wheel that’s still on the ground. No matter how high the bias ratio, you get no power to the ground.

During the transition from accel to decel, where you have near zero torque on the axle, even if the wheels are on the ground, the typical diff is unable to begin applying drive torque until AFTER the zero torque condition is over. While this condition is generally short-lived, the fact that most diffs can do nothing during that time means that there will be a delay once the zero torque condition stops - creating a reaction time in the driveline.

hmm... I just finish reading the detail section for 135 installation kit. It seems like it is what Mr. 5 did with his install, where he send in his stock diff, have them separate the welded ring gear then send it back to him for install. So there might be a long down time involve.

Besides, HPA is doing this also, ~$2000 for the completely assembled Diff + 800 core charge. So there's no down time. Unless Wavetrac is offering a better pricing, I might just go with HPA.

hmm... I just finish reading the detail section for 135 installation kit. It seems like it is what Mr. 5 did with his install, where he send in his stock diff, have them separate the welded ring gear then send it back to him for install. So there might be a long down time involve.

Besides, HPA is doing this also, ~$2000 for the completely assembled Diff + 800 core charge. So there's no down time. Unless Wavetrac is offering a better pricing, I might just go with HPA.

HPA and Wavetrac are working together.

You buy your final drive unit from HPA, then send you a complete unit with the Wavetrac diff installed and charge you a $800 core fee. You spend a Saturday swapping it our in your car, send back your core, get your $800 refund. Sounds like for ~$2000 and a Saturday of labor you will have LSD in the 135 right?